One Way the U.S. Navy Could Take on China: Diesel Submarines

What madman would propose adding diesel submarines to the U.S. Navy’s all-nuclear silent service?

There are a few . The topic came up at an early March hearing before the U.S. House Seapower and Force Projection Subcommittee. Representatives from three teams that have compiled competing “Future Fleet Architecture” studies convened to debate their visions with the committee. Published by the Navy Staff itself, the Center for Strategic and Budgetary Assessments, and the MITRE Corporation, the studies explore everything from overall ship numbers to the types of hulls comprising the future fleet to the mix between manned and unmanned platforms.

Navy potentates will now evaluate and compare the studies. The end product will be an official navy statement about force-structure questions, useful to Congress as lawmakers determine how many—and which—ships, planes, and armaments to fund. One consensus, however, already unites the protagonists to this debate: the U.S. Navy needs more of just about everything. The navy estimates it needs 355 vessels to fulfill its missions in increasingly contested settings, principally around the margins of Eurasia. That portends about a 30 percent boost to the force.

A naval expansion of such proportions will put a premium on low-cost yet effective platforms that can be acquired in bulk. Diesel-electric submarines constitute one such platform. The last boat in the Japan Maritime Self-Defense Force’s (JMSDF) Soryu class— a class widely acclaimed the world’s finest of its kind—ran Japanese taxpayers $540 million . Let’s use that as a benchmark for discussion. Meanwhile, each Virginia-class nuclear-powered attack boat sets back American taxpayers a cool $2.688 billion . That’s five for the price of one—a low, low price by any standard!

“If I was a country like China, I would buy a lot of diesels because I know you’re going to come and fight me here at home. We have to deploy, and the only way to deploy is to bring your own fuel with you. When we buy a Virginia, it comes with a lifetime of fuel. So I have nothing against diesel submarines, but you have to say, am I’m going to be fighting within 200 miles of where I’m based at? Or else now I have to buy extra oilers. I’m going to make them vulnerable when I refuel them; they’re going to have to snorkel and they’ll become vulnerable. It’s just not an option for us as long as we have to be a global navy."

He thus objected to diesels based on geography, logistics, and military capability. Let’s take those objections in turn. First, geography. Werchado’s critique seemingly presupposes that a U.S. diesel contingent would be based on U.S. territory—in other words, no closer to East Asia than Guam. QED: diesels are a non-starter. They would be positioned too far from the Yellow and East China seas, a likely combat theater, to do much good. And indeed, the cruising-range limitations on diesel boats are real and immutable. But let’s not overstate their impact. Distance can be managed through savvy force dispositions on the map.

In fact, if it does things wisely, the U.S. Navy can turn technical shortcomings to strategic and political advantage. Here’s how: it could procure a squadron of diesel boats in large numbers, station it permanently in the Far East, close to potential scenes of action, and place it under a combined U.S.-Japanese submarine command. Doing so would confer a host of benefits. Forward basing would obviate the range problem. For instance, Soryu-class boats boast a cruising range of 6,100 nautical miles—more than adequate for prowling the depths in Northeast Asia. A U.S.-Japanese force founded on a common hull—whether the Soryu or some other design—could presumably match or exceed this performance.

Nor would this represent some leap in the dark. Diesel subs have proven themselves in Northeast Asia across many decades—witness the U.S. submarine campaign against Japan during World War II . And after six-plus decades of practice dating to the JMSDF’s founding, Japanese subs excel at regulating east-west movement through the first island chain, as well as north-south movement along the East Asian periphery. Indeed, undersea warfare represented one of Japan’s chief contributions to allied strategy during the Cold War. Japanese boats lurked along the island chains to detect and trail Soviet subs trying to exit the Seas of Japan and Okhotsk for the broad Pacific Ocean. Soviet skippers commonly sheltered within Asia’s near seas rather than make the attempt.

This constitutes an ideal approach for an age when island-chain defense is regaining its prominence in allied maritime strategy. Want to deter China from seizing the Senkaku Islands or venturing other forms of aggression? Threaten something Beijing prizes dearly, namely ready access to the Western Pacific. Proliferate subs in Northeast Asia, and demonstrate the capability to use them to bar the straits piercing the first island chain. That should give Beijing pause when the leadership contemplates adventurism. If it’s good for China to procure diesels for anti-access/area-denial purposes in the near seas, then it’s good for Americans and Japanese if they want to deny the denier access it covets.